21700499 has 4 divisors (see below), whose sum is σ = 21781440. Its totient is φ = 21619560.

The previous prime is 21700493. The next prime is 21700501. The reversal of 21700499 is 99400712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21700499 - 2⁸ = 21700243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21700493) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40067 + ... + 40604.

It is an arithmetic number, because the mean of its divisors is an integer number (5445360).

Almost surely, 2^21700499 is an apocalyptic number.

21700499 is a deficient number, since it is larger than the sum of its proper divisors (80941).

21700499 is an equidigital number, since it uses as much as digits as its factorization.

21700499 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80940.

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 21700499 is about 4658.3794392471. The cubic root of 21700499 is about 278.9265832014.

The spelling of 21700499 in words is "twenty-one million, seven hundred thousand, four hundred ninety-nine".